1. Field of the Invention
The present invention relates to an improved system and method for increasing the read range, by a RFID scanner, a reader or an interrogator, of conventional FTX RFID tags.
2. Description of Related Prior Art
As is well known in the art, a RFID tag is a microchip which typically includes an antenna that is packaged in a such way that RFID tag can be applied to a variety of desired objects, animals or possibly human beings. An RFID tag, when receives and picks up an interrogation signal from an associated RFID scanner, reader or interrogator, transmits or sends a return signal(s) back to the RFID scanner, reader or interrogator. The RFID tag contains a data field identification information or encoded data field, e.g., a unique serial number, a unique customer account number, some other unique identifying indicia, etc., which is stored in an area of memory. It is to be appreciated that RFID tags come in many forms, but are typically relatively small and may be either active, passive or semi-passive.
As is well known in the art, RFID tags are commonly injected into pets or other animal animals in order to facilitate positive identification and cross indexing to medical records and other databases. It is possible that such RFID tags may also be incorporated or included as part of a component(s) transplanted into a human being, such as an artificial knee, an artificial hip, etc., and thereby subsequently utilized to identify the serial number, the model number, the date of installation, the manufacturer of the component, etc. Such product information is useful in the event that a defect, in the transplanted component, is eventually discovered and there becomes a need to recall such transplanted component(s).
As is well known in the art, RFID tags are typically interrogated by locating a handheld RFID scanner, reader or interrogator in close proximity to the location where the RFID tag resides, e.g., the area of the animal's skin accommodating the embedded RFID tag for example. The associated RFID scanner, reader or interrogator typically transmits and receives radio waves and is then combined with a digital signal processor that converts the waves into bits of information which can then be deciphered, by internal circuitry of the RFID associated scanner, reader or interrogator, in a conventional manner.
One problem with known prior art scanners and techniques is that they generally require the scanner to be located in very close proximity to the RFID tag, e.g., no more that a few inches or so, in order for the RFID scanner, reader or interrogator to read accurately the information stored on the RFID tag. In addition, many prior art RFID scanners, readers or interrogators typically “interrogate” the RFID tag for only a short duration of time, then turn off for a very short duration of time, and then continuously repeat this interrogation cycle of turning on/off until the data or information, stored in the data field on the RFID tag, is accurately read by the RFID scanner, reader or interrogator. It is to be appreciated that since the RFID scanner, reader or interrogator must be located very close to the RFID tag, it is sometimes quite difficult and time consuming to locate the RFID tag so as to facilitate accurate reading thereof.
The inventor has determined that there are two major factors which limit the useful range of the RFID scanner, reader or interrogator. These factors area (1) the RFID scanner, reader or interrogator has difficulty delivering enough signal, at 134.2 kHz, in order to adequately power the transponder, (2) the RFID scanner, reader or interrogator does not have a sufficient dynamic range in order to detect responses that may be 80 dB or more weaker than the 134.2 kHz carrier signal generated by the RFID scanner, reader or interrogator.